The concentrations of HCHO and C(4)H(4)O(6)KNa(.)4H(2)O were changed to control the Ni content of the Ni/CNT when the carbon nanotubes boiled in dilute nitric acid solution were immersed in Ni electroless plating bath without activating and sensitizing. Transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) analysis confirmed that the maximum content of Ni in the Ni/CNT was about 4.69 at.% and the maximum size of the Ni particles deposited on carbon nanotubes about 65 nm. Furthermore, the carbon nanotubes produced with the Ni/CNT were of high quality. (C) 2004 Elsevier B.V. All rights reserved.